This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this project we aim to establish novel high-resolution magnetic resonance imaging (MRI) technique, T1[unreadable], as quantitative methods sensitive to neuronal loss in the brain. We will investigate the predictive/discriminatory ability of the T1[unreadable] using a unilateral 6-hydroxydopamine (6-OHDA) PD mouse model (intrastriatal injection of 2 [unreadable]g 6-OHDA/[unreadable]L). We will study the functional relationship between T1[unreadable] with neuronal density in aphakia mice (where the deficit of dopaminergic neurons in substantia nigra and the pathways for survival of neurons are well investigated). Once validated, the technique proposed here can be used as a valuable tool to investigate if and how neuronal loss in substantia nigra is correlated with the progression of Parkinson's disease.